In general, pilot valves are used to actuate cylinders and other devices. A conventional three port pilot valve includes a pressurized fluid supply port, an output port, and an exhaust port. The conventional three port pilot valve also includes a piston and control valve. The control valve controls movement of the piston to provide an open passage between the pressurized fluid supply port and the output port, and at the same time to provide a closed passage between the output port and the exhaust port. The control valve also controls movement of the piston to provide an open passage between the output port and exhaust port and to provide a closed passage between the pressurized fluid supply port and the output port.
In the past, at least a five port pilot valve has been required in order to operate more than one device. Because of various applications for pilot valves, different types of pilot valves having different port arrangements have been required to control various types of devices in these different applications. Thus, the user has been required to maintain an inventory of pilot valves of different sizes and with different port arrangements.